Aujourd'hui, l'hétérogénéité des infrastructures de réseaux actuelles, ainsi que le manque d'interopérabilité en termes d'architectures et de cadres pour l'adaptation du contenu aux contextes des différents utilisateurs, empêchent les Prosumers (consommateurs-fournisseurs) d’offrir une haute qualité d'expérience sur différentes plates-formes et au travers de contextes diversifiés. Par conséquent, l'objectif de cette thèse est d'étudier, concevoir et développer une architecture novatrice, susceptible d'offrir la QoS/QoE garantie en exploitant efficacement les ressources disponibles et en adaptant dynamiquement la performance du réseau selon les environnements Réseau, Service et Utilisateur. Pour cela, l'architecture proposée est basée sur (1) un cadre de gestion distribuée qui exploite des mécanismes de réseau conscient du contenu pour identifier le contenu en transit et la correspondance sur les exigences de QoS/QoE, et sur (2) un mécanisme d'allocation des ressources de réseau et leur adaptation aux caractéristiques de QoS/QoE demandées. Un prototype de routeur de contenu a été réalisé, offrant des fonctions de reconnaissance du type de contenu et de routage suivant le contenu. Il propose un système de gestion synergique capable d'orchestrer les processus d'optimisation cross-layer pour les services de différenciation/classification et à termes une exploitation efficace des ressources. La validité de l'architecture proposée est vérifiée par un grand nombre d'expériences menées à l'aide d’infrastructures physiques et virtuelles. Un banc d'essai à grande échelle conforme aux spécifications de conception architecturale a été déployé pour valider l'approche proposée. / Today, the heterogeneity of current networking infrastructures, along with the lack of interoperability in terms of architectures and frameworks for adapting content to the various users’ contexts, prevent prosumers to deliver high QoE over different platforms and under diversified contexts. Consequently, the objective of this PhD thesis is to study, design, and develop a novel architecture capable to offer guaranteed QoS/QoE by efficiently exploiting the available resources and by dynamically adapting the network performance across the various Service, Network and User environments. To this end, the proposed architecture is based on (1) a distributed management framework that exploits Content Aware Network (CAN) mechanisms – on top of the Internet Protocol (IP) – for identifying content in transit and mapping its QoS/QoE requirements into specific network characteristics, and on (2) a network resource allocation mechanism for adapting the intra-domain resources to the requested QoS/QoE. A prototype Media-Aware Network Element (MANE) has been achieved, offering content type recognition and content-based routing/forwarding as a matter of guaranteed QoS/QoE provision in an end-to-end approach. Furthermore, it proposes a synergetic management system capable to orchestrate cross-layer optimization processes for service differentiation/classification, towards efficient resource exploitation. The validity of the proposed architecture is verified through a large number of experiments conducted using physical and virtual infrastructures. A large-scale test-bed conforming to the architectural design specifications was deployed for validating the proposed approach.

In this thesis, we tackle the problem of designing and implementing a wireless video sensor network for a surveillance application. The goal was to design a low power content aware system that is able to take an image from an image sensor, determine blocks in the image that contain important information and encode those block for transmission thus reducing the overall transmission effort. At the same time, the encoder and the preprocessor must not consume so much computation power that the utility of this system is lost. We have implemented such a system which uses a combination of Edge Detection and Frame Differencing to determine useful information within an image. A JPEG encoder then encodes the important blocks for transmission. An implementation on a FPGA is presented in this work. This work demonstrates that preprocessing gives us a 48.6 % reduction in power for a single frame while maintaining a delivery ratio of above 85 % for the given set of test frames.

The visualization of the high-dimensional feature landscapes that are encountered when analyzing audio data is a challenging problem and is the focus of much research in the field of Music Information Retrieval. Typical feature sets extracted from sound have anywhere from dozens to hundreds of dimensions and have complex interrelationships between data elements. In this work, we apply various modern techniques for the visualization of audio data to a number of diverse problem domains, including the bioacoustics of Orcinus Orca (killer whale) song, partially annotated chant traditions including Torah recitation and the the analysis of music collections and live DJ sets. We also develop a number of graphical user interfaces to allow users to interact with these visualizations. These interfaces include Flash-enabled web applications, desktop applications, and novel interfaces including the use of the Radiodrum, a three-dimension position sensing musical interface.

Video streaming is used daily by people around the world, plays a big role in many Internet users daily lives, and are today responsible for the majority of the Internet traffic. As 360 video streaming services become increasingly popular and each such user session requires much higher bandwidths than traditional video streaming, optimized solutions for this type of video is becoming increasingly important. One method that has been proposed to reduce the bandwidth usage is the usage of proxy servers. In this thesis, we evaluate custom-adapted prefetching policies that tries to improve the users Quality of Experience (QoE). Defining a prefetching policy for something adaptive as 360 video brings challenges that need to be simulated before release in the real world. Without proper testing the prefetch policy can do more harm than good by flooding the network with unnecessary amount of transmissions. Prior research has shown that the QoE of HTTP-based adaptive streaming (HAS) clients can be improved with content-aware prefetching (e.g., Krishnamoothi et al. 2013). However, there have been limited prior work adapting and evaluating such policies in the context of 360 streaming. This thesis presents a simulation-based evaluation of proxy-assisted 360solutions that includes custom designed prefetching polices. The main contributions of the thesis are as follows:First, we implement four types of proxy-assisted prefetching policies and simulate these under two scenarios with different networks conditions. One scenario simulate a network environment with a bottleneck located between the client and proxy while the other scenario simulates a network environment with the bottleneck located between the proxy and server. The cooperation between the client and proxy is evaluated for each scenario and prefetching policy. Second, we evaluate the proxy-assisted prefetching policies in comparison with baselines and each other, in regards of their ability to improve the viewers QoE. Our results show that the bottleneck location has major impact on proxy-performance and that simple prefetching policies can enable clients to download bigger loads of data, which have a significant effect on viewers QoE. Considering that 360 videos require much higher bandwidth then traditional video streaming, service providers may consider integrating prefetching policies for 360 video streaming.

La tendance et l'absolu nécessité d'aujourd'hui est de construire l'Internet du futur. De nombreuses actions de recherche sont menées dans ce sens et la plupart d'entre elles décrivent le domaine des médias comme l'un des plus prédominants et essentiels à prendre en considération. En effet, le contenu média est déjà dominant sur Internet et ne cesse d'augmenter alors que l'architecture actuelle n'avait pas été construite avec les médias en tête. La diffusion efficace de contenu multimédia devient maintenant une évolution nécessaire non seulement pour plaire aux utilisateurs finaux, mais aussi pour révéler de nouvelles opportunités d'affaires pour tous les acteurs de la chaîne de valeur. Dans cette thèse, nous proposons une nouvelle architecture pour l'avenir des réseaux de médias Internet, centrée autour du concept d'une approche collaborative gagnant-gagnant entre tous les acteurs. Le "Networked Media écosystème" que nous nous efforçons de construire permettra de nouvelles fonctionnalités et des avantages pour toutes les parties prenantes, essentiellement grâce à l'innovation basée sur la prise de conscience qu'il permet et leurs résultats en termes d'amélioration de la qualité et de l'adaptation. L'approche proposée repose sur: (1) une couche Home-Box virtuelle, qui d'une part prend en compte le Contexte et le Réseau au niveau de l'Application afin de permettre un système de diffusion de contenu efficace et, d'autre part, fournit des informations pour mettre en œuvre la conscience du contenu au niveau du Réseau; (2) une couche réseau basée sur le Contenu (CAN), dont le rôle est d'examiner les informations relatives au contenu transporté et de prendre les mesures appropriées, en plus de fournir de l'information aux couches supérieures. L'architecture proposée n'a pas seulement été conçue et simulée, mais aussi mise en œuvre et validée par le projet européen nommé ALICANTE. Ce projet a permis de fournir des résultats intéressants et a ouvert la voie à des évolutions et des orientations futures de la recherche dans le domaine des Réseaux de Média.

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.

Computer screens are very small compared to the size of large information spaces that arise in many domains. The visualization of such datasets requires multiscale navigation capabilities, enabling users to switch between zoomed-in detailed views and zoomed-out contextual views of the data. Designing interfaces that allow users to quickly identify objects of interest, get detailed views of those objects, relate them and put them in a broader spatial context, raise challenging issues. Multi-scale interfaces have been the focus of much research effort over the last twenty years.There are several design approaches to address multiscale navigation issues. In this thesis, we review and categorize these approaches according to their level of content awareness. We identify two main approaches: content-driven, which optimizes interfaces for navigation in specific content; and content-agnostic, that applies to any type of data. We introduce the content-aware design approach, which dynamically adapts the interface to the content. The latter design approach can be used to design multiscale navigation techniques both in 2D or 3D spaces. We introduce Arealens and Pathlens, two content-aware fisheye lenses that dynamically adapt their shape to the underlying content to better preserve the visual aspect of objects of interest. We describe the techniques and their implementation, and report on a controlled experiment that evaluates the usability of Arealens compared to regular fisheye lenses, showing clear performance improvements with the new technique for a multiscale visual search task. We introduce a new distortion-oriented presentation library enabling the design of fisheye lenses featuring several foci of arbitrary shapes. Then, we introduce Gimlens, a multi-view detail-in-context visualization technique that enables users to navigate complex 3D models by drilling holes into their outer layers to reveal objects that are buried into the scene. Gimlens adapts to the geometry of objects of interest so as to better manage visual occlusion problems, selection mechanism and coordination of lenses.

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.

As the fidelity of computer generated imagery has increased, the need to digitally create convincing natural phenomena like fluids has become fundamental to the entertainment production industry. Because fluids are complex, the underlying physics must be computationally simulated. However, because a strictly physics-based approach is both computationally expensive and difficult to control, it does not lend itself well to the way artists and directors like to work. Directors require control to achieve their specific artistic vision. Furthermore, artistic workflows rely on quick iteration and the ability to apply changes late in the production process. In this dissertation we present novel techniques in adaptive simulation and fluid post-processing to improve artistic workflows for fluid simulation. Our methods reduce fluid simulation iteration time and provide a new way for artists to intelligently resize a wide range of volumetric data including fluid simulations. To reduce iteration time, we present a more cache-friendly linear octree structure for adaptive fluid simulation that reduces the overhead of previous octree-based methods. To increase the viability of reusable effects libraries, and to give artists intuitive control over simulations late in the production process we present a ``fluid carving" technique. Fluid carving uses seam carving methods to allow intelligent resizing on a variety of fluid phenomena without the need for costly re-simulation. We present methods that improve upon traditional seam carving approaches to address issues with scalability, non-rectangular boundaries, and that generalize to a variety of different visual effects data like particles, polygonal meshes, liquids, smoke, and fire. We achieve these improvements by guiding seams along user-defined lattices that can enclose regions of interest defined as OpenVDB grids with a wide range of shapes. These techniques significantly improve artist workflows for fluid simulation and allow visual entertainment to be produced in a more intuitive, cost-effective manner.